alexandria would be a read heavy load, books read and commented vs. uploading of the books
Discussion
almost exclusively. The relay doesn't have to be a relay, kind if just needs a database (or files tbh) and some good caching.
http api like the one i made
badger has a good read cache on it as well, and it's designed to split the read/write load mainly in favor of writing indexes because events don't change, also, scanning the key tables is fast because it's not interspersed with value read/write